[Leica] IMG: Testing SL For Milky Way Imaging

[Robert Adler]

Thanks Jim. I'll give it a try.
Best,
Bob


Bob Adler
www.robertadlerphotography.com
*"Capturing Light One Frame At A Time"*

On Fri, Jun 23, 2017 at 9:26 AM, Jim Nichols <jhnichols at lighttube.net>
wrote:

> Bob, when I need to reduce the noise in images, I turn to Neat Image.  It
> requires some experimentation, but works if the amount of reduction is kept
> to a low level.  I think there is a trial version still available.  I have
> used it as a stand alone tool, and currently have it as a plugin in
> Photoshop CC.
>
> Jim Nichols
> Tullahoma, TN USA
>
> On 6/23/2017 11:14 AM, Robert Adler wrote:
>
>> Hi Howard,
>> Thank you for this workflow of yours. It's very helpful and much
>> appreciated.
>> I will send you the raw file using the 12,500 ISO. I'd be very curious if
>> you have more luck removing the noise. I'm going to play with the DxO
>> noise
>> program today to see how that works. Noise can be the killer of an image:
>> this one is borderline. The NIK Dfine is not working anymore for me and is
>> discontinued. I'd love to remove noise in CC, but I don't really
>> understand
>> how to do it: hit and miss. This despite reading tons about it.
>> Thanks again and appreciate your expertise.
>> Best,
>> Bob
>>
>>
>> Bob Adler
>> www.robertadlerphotography.com
>> *"Capturing Light One Frame At A Time"*
>>
>> On Thu, Jun 22, 2017 at 8:49 AM, Howard L Ritter Jr <hlritter at twc.com>
>> wrote:
>>
>> That’s a very nice capture of the region towards the center of the Galaxy,
>>> Bob. And even expanding the image on my screen, I don’t see any
>>> bothersome
>>> noise. There’s virtually none in the dark regions of the hills, and the
>>> mottling in the lake and the sky I think is primarily due to the
>>> innumerable stars. In any case, the SL’s performance at ISO 12500 is
>>> impressive. That region is my favorite binocular target, and now that
>>> I’ve
>>> discovered how to nearly eliminate the effects of light pollution in my
>>> suburban sky, and begun to do sky imaging, it will be a target for that
>>> as
>>> well.
>>>
>>> I don’t recall whether you mentioned seeing them when I first posted
>>> them,
>>> but I took some similar shots of the Southern Hemisphere Milky Way from
>>> Australia in April. I took them with a Nikon D810A (the astrophotography
>>> model with the less IR-restrictive sensor cover plate) and the Nikon
>>> 14-24mm zoom at 14mm or the 24-85mm zoom at 50 or 85mm. The shots with
>>> the
>>> zoom were done with the camera on a tracking device to avoid star
>>> trailing.
>>> I used ISOs of 1600-6400.
>>>
>>> http://gallery.leica-users.org/v/hlritter/Gallery_001/ <
>>> http://gallery.leica-users.org/v/hlritter/Gallery_001/>
>>>
>>> I stretched the histogram of my images in PS by moving the white-point
>>> slider to brighten the stars and the black-point slider to darken the
>>> background sky, then fiddled with both, plus the grey-point slider, to
>>> get
>>> the effect I wanted. To get rid of vignetting, I also applied a
>>> flat-field
>>> correction frame that I took in daylight with a couple of layers of white
>>> T-shirt over the lens, and the camera aimed away from the sun at a sunlit
>>> scene, and then converted to greyscale. I think my images as posted are a
>>> bit hyper-real, but that’s a goal of photographing any celestial targets
>>> other than the bright moon and planets. In any case, they carry the
>>> flavor
>>> of the visual impact of seeing the Southern Milky Way and the Magellanic
>>> Clouds, for the first time, from the deep darkness of rural Australia.
>>> The
>>> left side of the region of the MW that I imaged adjoins on the right your
>>> region of the MW at the dense star cloud in the center of your first
>>> image.
>>> The very different orientation of the MW is what happens when your
>>> viewpoint is rotated 65 degrees clockwise!
>>>
>>> Did you do any post-processing of these images? They have the look of raw
>>> images to me. If so, I’d be interested to see what the result of a
>>> histogram stretch might be. Would you mind sharing the raw file with me
>>> so
>>> I can play a little? I’ve added a couple of the raw images to my album so
>>> you can see the difference post-processing makes.
>>>
>>> It’s possible to see very short star trails by enlarging your images. The
>>> rule of thumb is that they won’t be easily noticeable if the exposure
>>> time
>>> is not more than 300 sec divided by the FL in mm, so your 20-sec
>>> exposures
>>> at 24mm are pushing it. If you’re going to do much of this sort of
>>> thing, a
>>> camera tracker can be had for about the price of 2 or 3 SL batteries… 😉
>>> Some of my images were exposed for longer than the rule of 300, which is
>>> possible when the region being imaged is well away from the celestial
>>> equator, where the stars move fastest.
>>>
>>> (Pardon me if I’m telling you things you already know!)
>>>
>>> —howard
>>>
>>>
>>> On Jun 21, 2017, at 5:28 PM, Robert Adler <rgacpa at gmail.com> wrote:
>>>>
>>>> Last night I went up to Silver Lake in the Sierras. It's at about 7,800'
>>>> elevation. I went to see how the SL with the SL24-90mm would work with
>>>> Milky Way photography. The two images were taken at 12,500 ISO @ 24mm,
>>>> f/2.8 with a 20second exposure. I shot from 10:30pm until 3:00am...
>>>>
>>>> Though there is a lot of noise, I don't find it distracting. The drama
>>>> of
>>>> the center of our galaxy seems to outweigh any noise issues. Please
>>>> click
>>>> on the image to make it larger to fit your screen:
>>>>
>>>> http://www.robertadlerphotography.com/p133735760/h8e052599#h8e052599
>>>>
>>>> I would appreciate others' opinions as to whether or not they find the
>>>> noise distasteful or does it look more like film grain. The images were
>>>> post processed in Capture 1.
>>>>
>>>> Thanks for any opinions in advance,
>>>> Bob
>>>>
>>>>
>>>> Bob Adler
>>>> www.robertadlerphotography.com
>>>> *"Capturing Light One Frame At A Time"*
>>>>
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